Merge branch 'ab/hooks-regression-fix'

Merge branch 'ab/hooks-regression-fix'

In Git 2.36 we revamped the way how hooks are invoked.  One change
that is end-user visible is that the output of a hook is no longer
directly connected to the standard output of "git" that spawns the
hook, which was noticed post release.  This is getting corrected.

* ab/hooks-regression-fix:
  hook API: fix v2.36.0 regression: hooks should be connected to a TTY
  run-command: add an "ungroup" option to run_process_parallel()